Grinding wheel



Sept. l5, 1970 R, C, FRANKLJN ETAL 3,528,203

GRINDING WHEEL Filed May 2, 1968 INVENTORS GMX/m.,

`United States Patent O 3,528,203 GRINDING WHEEL Robert C. Franklin and Richard O. Lane, Jackson, I VIich., assignors to The Bendix Corporation, a corporation of Delaware Filed May 2, 1968, Ser. No. 725,997

Int. Cl. B24b 41 /00 U.S. Cl. 51-168 5 Claims ABSTRACT 0F THE DISCLOSURE A grinding wheel mountable on an arbor by engagement with a pair of flanges and deformable blotters having radially oriented ridges in its lateral surfaces at the flange portion.

BACKGROUND OF THE INVENTION Field of the invention Grinding wheels and more particularly grinding wheels constructed of abrasive grains for mounting on an arbor.

Description of the prior art It is well known in the art that slippage between a grinding wheel and the arbor on which it is mounted may precipitate breakage of the wheel. It will be appreciated that a wheel breaking while rotating at high speed can eject sizable sections of abrasive material at velocities which can cause extensive injury to nearby persons.

In the past, abrasive grain size irregularities in the lateral surfaces of grinding wheels have provided a convenient means for preventing relative rotation of the wheel with respect to an arbor. More particularly, blotters which are deformable to conform to the irregularities are used in combination with rigid flanges to mount the wheel to an arbor. The blotters are placed adjacent the lateral sides of the grinding wheel and are pressed into its sides to conform to the irregularities by a compressive force applied by a pair of flanges. Slippage between the wheel and the blotters is prevented by a meshing effect between the deformable blotters and the irregularities of the grinding wheel. In turn, slippage between the blotters and the flanges is prevented by frictional engagement between the two. The pressure distribution across the face of the flange is uniform since the irregularities are small and therefore any possible variance of the pressure distribution due to these irregularities is effectively cancelled by the deformable blotter. As a result of this uniform pressure distribution, a highly efficient frictional engagement between the blotter and the flange results.

Recent developments in grinding wheel molding techniques have resulted in wheels with smooth lateral surfaces. The new bonding techniques are used to add strength to compensate for increases in operating speed, load and temperature. When these new wheels are used in combination with blotters and flanges, slippage occurs between the blotter and the wheel due to a lack of meshing engagement heretofore provided by the grain-size irregularities. This problem is compounded by the increased operating speeds and loads. It has previously been dealt with by roughening the sides of the wheel by rolling heavily-loaded hardened spheres over the surface to disintegrate the outermost layer of the lateral sides of the grinding wheel and thereby expose a layer having grainsize irregularities. This operation has proven to be prohibitively costly.

Under the present state-of-the-art, it is not possible to mold grain-size irregularities into the lateral surfaces of the wheel. Rather, any projection or molded feature must have a dimension being substantially more than a single grain size. Therefore, the naturally occurring irregular- Mice ities could not be readily substituted for by molded-in irregularities of the same dimensions. The use of irregularities of substantially greater dimension than grain size was thought to be unfeasible because the greater dimension has a pressure effect that is transmittabl through the blotter thereby creating a uniform pressure distribution across the face of the flange. It has been believed that the nonuniform pressure distribution would prevent efficient frictional engagement between the flange and blotter. Accordingly, it was considered necessary to provide flanges having corresponding patterns of irregularities machined into their faces to provide even pressure distribution and acceptable non-slipping engagement between the grinding wheels and flanges. Machined flanges, however, are relatively costly and frequently become unserviceable due to wear caused by the abrasive environment to `which they are subjected.

SUMMARY OF THE INVENTION The present invention provides a grinding wheel for use with flanges having smooth faces having a molded pattern in its lateral sides which effectively prevents motion between the wheel and an arbor on which it is mounted. The grinding wheel according to this invention has a plurality of radially oriented ridges in its lateral surfaces in the area of flange engagement which are substantially greater in peak-to-valley height than the size of average abrasive grains of the wheel. The radially oriented ridges provide both an effective frictional engagement between the blotter and the flange and a strong intermeshing effect between the ridges and the deformable blotter. The uneven pressure distribution on the face of the flange has no adverse effect in the case of radially oriented ridges. Advantageously, the cost of producing the wheel is not significantly increased by the addition of the molded pattern nor is its strength reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective, exploded view of a grinding wheel assembly according to this invention.

FIG. 2 is a perspective, exploded view of another wheel assembly according to this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a grinding wheel 10 constructed of abrasive grains having a hole 12, periphery 14 and lateral surfaces 16 is shown. Although FIG. 1 is shown as an eX- ploded view to facilitate the teaching of the present invention, the structures shown therein will be described with respect to their operating positions. The lateral surfaces 16 are provided with a plurality of ridges 18 eX- tending radially from the grinding wheel axis 20 in the portions 22 which correspond to the engagement of the vblotters 24 and the flanges 26. Since presently available blotters and flanges are circular in shape, it is preferred that the ridges are defined by inner and outer circles approximately corresponding to the mating part of the flanges 26. The flanges 26 are mounted on an arbor 28 in a manner such that flange bosses 30 hold the Wheel 10 in coaxial relationship with respect to the arbor 28. A compressive force is placed on the flanges 26 -by a clamping nut 32 threaded onto the arbor 28 which force is transmitted to the wheel 10 through the blotters 24. As can be seen in the drawings, the flanges 26 are provided with flat faces 34 which are in frictional engagement with the deformable blotters 24 which are in turn in meshing engagement with the ridges 18 of the Wheel 10. The ridges 18 shown in this view are impressed into the lateral surfaces 16 of the wheel 10 such that the peaks of the ridges are flush with the lateral surfaces 16. This construction is preferred since it permits stacking of the molded Wheels before they are hardened in the bonding process without deformation of the ridges 18. The peak-to-valley height of the ridges 18 is substantially greater than the average abrasive grain size of the Wheel 10. As such, the ridges may be conveniently provided by state-of-the-art molding techniques. In particular, the ridges 118 have been suitably provided by placing an adaptor ring having the ridges formed thereon in a conventional grinding wheel mold.

In FIG. 2, another grinding wheel 110 according to this invention is illustrated. The wheel 110 has a hole 112 for direct mounting of the wheel on the arbor 128 and a concentric periphery 114. In this embodiment, the lateral sides 116 of the wheel 110 are provided with a plurality of radially oriented ridges 118 which are elevated above the surface of the lateral sides 116. A pair of deformable blotters 124 are provided to intermesh with the ridges 118 on their one side and to frictionally engage a pair of flanges 126 on their other side. The flanges 126 are of a common disc shape which are particularly suited for mating with a grinding Wheel having elevated ridges 118. Flanges of this construction may also be used with ridges which are recessed as shown in FIG. 1. As in the previous case, the flange faces 134 are flat. A nut 132 is threadable on arbor 128 to provide a compressive force which is transmitted through flanges 126 and blotters 124 to the wheel 110.

In practice, the ridges have proved to effectively prevent slippage between grinding lwheels and arbors when used in combination with conventional at-faced anges. It is therefore believed to be a significant advancement in the art.

Although this invention has been disclosed and illustrated with reference to a particular application, the principles involved are susceptable to numerous other applications which will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

Having thus described our invention, we claim:

1. A grinding wheel constructed of abrasive grains of the type which is mountable on an arbor by a pair of blotters disposed adjacent corresponding portions of opposite lateral surfaces of said wheel and a pair of anges disposed adjacent said blotters which apply a compressive force to said wheel portions through said blotters, said wheel having a plurality of radially oriented molded ridges at said Wheel portions which are substantially greater in peak-to-valley height than the average size of said grains.

2. The grinding Wheel of claim 1 wherein said ridges are entirely above the lateral surface of the wheel.

3. The grinding Wheel of claim 1 wherein the peaks of said ridges are flush with the lateral surface of the Wheel.

4. A grinding -wheel assembly comprising:

a grinding wheel constructed of abrasive grains having a central hole therethrough for passage of an arbor upon which the wheel is mounted and a plurality of radially oriented molded ridges at predetermined portions in the lateral surfaces thereof being substantially greater in peak-to-valley height than the average size of said grains,

a pair of deformable blotters disposed adjacent said wheel portions, and

ange means disposed adjacent said blotters for applying a compressive force to said wheel portions through said blotters.

5. The grinding wheel of claim 4 wherein said ridges are entirely above the lateral surface of the wheel.

References Cited UNITED STATES PATENTS 2,785,515 3/1957 Sansig 51-168 1,944,489 1/1934 Bockshe 51-168 489,149 l/1893 Hyde 51--168 FOREIGN PATENTS .669,003 12/ 1938 Germany.

40 JAMES L. JONES, J R., Primary Examiner 

